Method of and apparatus for opening plugged pipe in a well bore



L. K. MOORE 2,935,130

METHOD OF AND APPARATUS FOR OPENING PLUGGED PIPE IN A WELL BORE May 3,196.0

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L. K. MOORE May 3, 1960 METHOD OF AND APPARATUS FOR OPENING FLUGGED PIPEIN A WELL BORE Filed April 10, 1956 4 Sheets-Sheet 2 l, INVENTOR. weave:K. 4/0026 L. K. MOORE May 3, 1960 METHOD OF AND APPARATUS FOR OPENINGPLUGGED PIPE IN A WELL BORE Filed April 10, 1956 4 Sheets-Sheet 3 M mamy mz a N 5 e w v. B

L. K. MOORE May 3, 1960 METHOD OF AND APPARATUS FOR OPENING FLUGGED PIPEIN A WE'LL BORE 5 H RM M MN 3% m m a 2 M w 9 a 4 0 0 6 6 p 5 0 0 g E/ 44 a M. x a l w. /M 1, iii 0 III 1 w m w M i \\\\\\\Q\\ d n F 2 u l :1 k

clean out the plug to regain circulation.

METHOD OF AND APPARATUS FGR OPENING PLUGGED- PEPE IN A WELL BORELawrence K. Moore, Natchez, Miss.

Application April 10, 1956, Serial No. 577,365

.. ll-Claims. (Cl. 166-44) This invention relatesv to apparatus suitablefor use on 'a wire line' or cable for cleaning out material cloggingthe'bore of a continuous length of pipe or separated collars, tubing,jars, bumper subs and the like in a well, and more particularly to amethod and apparatus for both cleaning out and carrying away cuttingsand debris plugging such pipe or fish in an oil or gas well, or wellbeing drilled for such a purpose.

This application is a continuation-in-part of my copending applicationSerial No. 349,385, entitled Hydraulic Clean-Out Apparatus for OpeningPlugged Well Pipe, filed April 17, 1953, and now abandoned.

The inside of a continuous length of pipe disposed in a well bore maybecome plugged with heavy or dehydrated mud or lost circulationmaterial, and a fish left in a well may become additionally plugged withwall cuttings and debris which may fall into the top of the fish.

It is desirable to clean out the bore of a continuous length of pluggedpipe or fish for any one. of a number Thus, forexample, it may benecessary to In addition, it may be necessary to remove such a. plug inorder to run some form of wire line tool, suchas a free point inofreasons.

dicator, back-off tool, or gun perforator to a point in the pipe or fishbelow the plug. The running of any of the above-mentioned wire-linedevices, after removal of the plug, will usually greatly facilitaterecovery of the plugged pipe or fish from the well bore.

, Prior to my invention a conventional method for cleaning out a pluggedstring of drill. pipeor tubing, or for cleaning out afish, included thesteps of lowering a continuous stringof smaller pipe into the pluggedpipe. or tubing and washing out the plug by a circulation of fluiddownwardly inside the smaller pipe. This method ob.- viously was verytime-consuming and expensive for the reason that the smaller pipe mustfirst be secured, transported to the location, and made up in individualjoints. While all these preparations were made, the string of pipe to bewashedv out could, in addition, stick higher in the hole.

Another method consists of running spudding tools on a wire line in anattempt to knock the bridge out of the pipe or fish. This, obviously, isnot always effective if the plug extended over any long interval in thepipe, for

I the reason that there is no means of actually removing the pluggingmaterial. from the pipe. Still another method consists of the running ofsmall-diameter hydrostatic bailers on a wire line and attempting to bailthe material from the pipe. This method has, serious limitations in thatthe bailer can only bring outsmall amounts of; material on each. run,thus requiring many runs in the hole. In addition, the washing orloosening effect of thebailer is often not efiectivev in breaking up thematerial so that it can enter the bailer, and further, bailers of thistype often, tend. to stick, thus further complicating the fishing job.Thus, prior to my invention, if any of U ited States Pa en lengths ofpipe called a fish,such as drill pipe, drill ice the above-mentionedmethods failed to unplug the pipe or fish, the only alternatives were toremove the pipe by making outside mechanical cuts when possible, whichis a very expensive method, or abandoning that portion of the pluggedpipe remaining in the hole.

It will be readily appreciated by those skilled in the oil well drillingart that my hydraulic clean-out device, that can be run on a wire lineor cable and thus wash out as much as 500 feet of plug on one run, wouldsave considerable time and be much more etfective and advantageous thanany of the conventional methods mentioned above. I p The presentinvention provides a method operable with a. wire line or cable forcleaning out the bore of a'plugged pipe or fish comprising theoperational steps of; lowering means forming a nozzle into andcompletely below the upper end of the pipe, such as, for example, drillpipe or tubing disposed in a well bore above a plugged fish; andcirculating a fluid downwardly inside the drill pipe or tubing andthrough the nozzle-forming means at ,a pressure to form a jet of fluidat the lower end of the nozzle-forming means, whereby material pluggingthe pipe or fish may be eroded or washed out of the bore of the pipe orfish by the force of the jet and carried away by fiow of the fluidthrough perforated holes, circulation ports, or a break in the pipe, andupwardly between the well bore and the unplugged pipe. It will beappreciated that a skirt, overshot or washover pipe may be appended tothe unplugged pipe and positioned to surround the plugged pipe wherebyfluid will circulate through the nozzle forming means into the fish,through said skirt, overshot or washover pipe and then upwardly in thewell bore.

In my method, the nozzle-forming means may be easily lowered into thewell by a conventional wire line or cable. It is well known by thoseskilled in the art as aforementioned that a wire line may be run into awell at an extremely faster rate than a continuous length, of smalltubing or small drillpipe which must be lowered section by section.Hence, the present invention provides a more eificient and economicalmethod of cleaning out material plugging the bore of a fish.

The word pipe as used above, and as usedhereinafter is meantto includenot only the usual string of drill pipe, but also the usual string ofproduction tubing.

This pipe is. an outerpipe, and in practicing my invention, I usuallyemploy a smaller pipe or tubular meritber which is usually externallyflush and which is hereinafter referred to as tubing for use inside ofsaid outer pipe which I refer to as pipe. It will be appreciated, thatthe outer pipe, i.e. drill pipe or production tubing, may be providedwith threads or a threaded sub to engage the fish. It will beappreciated still further that, said pipe may be provided with, othermeans of engaging the fish, such as an overshot equipped with slips.

According to a feature of the invention, a section of small-diametertubing is lowered into a pipe in a well on a wire line or cable to aposition substantially below the upper end of said pipe and near itslower end or near a, plug in thev pipe. The external surface of thetubing is sealed or partially sealed to the internal surface of the pipeat least at one point along the length of the tubing. The tubing is thenbrought into close relationship with debris plugging the pipe or fish. Afluid is thereafter circulated through the pipe and subsequently throughthe tubing and into contact with the debris plug ging the pipe or fishto erode and remove the same from the pipe or fish. In accordance withthis feature. of the invention, the tubing is lowered and/or pumpedfarther into the pipe or fish as the plugging material is-eroded orwashed out of it so that the jet may be positioned a most effectivedistance from the material plugging the pipe or fish.

According to a specific aspect of the invention the tubular member ornozzle to be loweredin a pipe is provided with apertures and means areprovided to lower the tubing into the pipe. Collar means are alsoprovided slidable on the tubing and resilient means are fixed to thetubing to urge the collar means upwardly along the tubing to cover theapertures. The sealing means are then fixed to the collar means, wherebythe collar means -may be forced downwardly against the resilient meansto open the apertures to relieve stress on the lowering means any timethe fluid pressure in the pipe above the tubing section becomesexcessive. V i The sealing means for use in pipe may comprise a tubinganchor including a length of tubing or hollow body portion having afirst radial projection on its lower end. In this case a tubing isprovided with a second iradial projection and'is disposed concentricallywith and contiguous to the body portion of the tubing anchor whereby theradial projection of the tubing section may engage the first radialprojection of the body portion to limit the downward movement of thetubing section along the body portion. The tubing section is thenslidably mounted on the body portion to be always positioned a mosteffective distance from the material plugging the pipe or fish.

According to a still more specific feature of the invention, the sealingmeans includes-an annular resilient body as tubing, packing meansslidable on the tubing to provide a fluid-tight seal between the saidpipe and the tubing, check means on the tubing for limiting downwardmovement of the packing means thereon, and a shoulder on the pipe tolimit downward movement of the packing means therein. In case thepacking means should come off of the tubing, the shoulder on the pipeinsures that the packing means will not fall into the bottom of the wellwhere it might cause damage or where considerable trouble might beencountered in retrieving it.

According to a specific feature of the invention, a wire line orflexible cable is connected to the tubing so it may be easily loweredinto and lifted out of the well.

An aspect of the invention involves the use of a cir- .culating headconnected between the flexible cable and the tubing to providecommunication from the pipe above the packing means through-the upperend of the tubing. In addition, an outwardly-extending shoulder may beprovided at the upper endof the tubing to prevent it from fallingthrough the packing means in the event that the flexible cable becomessevered accidentally.

In accordance with another feature of the invention, the check means maycomprise a member associated with the tubing to shear when sufiicientforce is applied to the tubing, whereby the tubing may be removed fromthe pipe -if the packingmeans becomes stuck in the'pipe.

. It is, therefore, an object of the invention to provide an improvedmethod of cleaning out a plugged pipe or fish inawell bore. v p

' It is a further object of the invention to provide means suitable foruse on a wire line or cable for washing-out the bore of a plugged pipeorfish. i

It is another object of the invention to provide a device for preventingseparate component parts of a clean-out tool from falling into a well.

1 A further object of the invention is to provide means 4 for preventingapparatus useful for cleaning out a plugged pipe or fish from becomingstuck in pipe in a well.

These and other objects and advantages of the present invention will bebetter understood when considered with the following description takenin connection with the accompanying drawings made a part of thisspecification, wherein several embodiments are illustrated by way ofexample. The device of the present invention is by no means limited tothe specific embodiments illustrated in the drawings since they areshown merely for purposes of description.

Fig. 1 is an elevation view of a well derrick and other apparatusgenerally required for performing the method of the invention;

Fig. 2 is a broken away sectional view of a tubing auchor shown employedwith other apparatus of the invention to clean-out material plugging afish in a well bore;

Figs. 3 and 4 are broken sectional views of alternative embodiments ofthe invention to be used with the apparatus shown in Fig. 2; I

Figs. 5, 6 and 7 are broken away sectional views of three forms ofanother embodiment of the invention;

Fig. 8 is a sectional view of another clean-out apparatus constructed inaccordance with another embodiment of the invention;

Fig. 9 is a sectional view of a portion of the apparatus shown in Fig. 8in its operative position to clean-out material plugging a fish; and

Fig. 10 is a sectional view of a sub connected between the lower end ofa drill pipe and the upper end of a fish to provide circulation portswhen it is desirable to screw the unplugged pipe into the fish.

In the drawings in Fig. 1 a derrick 10 is shown provided with a crownblock 12 over which a wire line or cable 14 is disposed into a well, notshown. A table 18 is shown above the well which is operated by amechanism 16 that also lowers and hoists the wire line 14 into and outof the well. A pump assembly 20 is also provided to circulate wash fluiddown through the drill pipe and up between the well bore and thedrill'pipe.

A tubing anchor 22, which may be employed with the method of theinvention, as shown in Fig. 2 comprising a body portion or length oftubing 24 having a lower extremity or stinger 26. The stinger 26 isprovided with nozzle-forming means at the bottom thereof to erode'outmaterial 28 plugging a fish 30. The fish 30 is disposed below a sectionof drill pipe 32 in a well bore 34. It is to be specially noted that thetubing anchor 22 may be lowered in on the wire line 14 and set in thepipe 32. The tubing 24 is threaded into a head 36 which is, in turn,threaded into a circulating head 38 having apertures 40 to permit washfluid pumped down the pipe 32 to enter the tubing 24 at its upper end.The wash fluid is then forced out of the lower end of the stinger 26 tocleanout the fish 30.

The tubing anchor 22, as shown in Fig. 2, is not fixed in the pipe 32.However, this may be'accomplished easily in a well known'andconventional manner. The tubing anchor 22, in addition to the head 36,comprises a sealing packer 42 disposed on the outside and at the lowerend of the head 36, an expander sleeve 44 disposed on the outside of thetubing 24 and having fingers 46 extending up into the space between thepacker 42 and the head 36. A slip assembly 48 there shown includes acylinder portion 50 surrounding the tube 24 for supporting three sets ofslips 52 by means of suitable spring extensions 54. Drag springs 56 arealso provided "on the cylinder 50 to set the tubing anchor in the pipe32. A screw 58 is-disposed in the cylinder 50 to guide the cylinder 50up and down along the tubing 24, the screw 58 riding in a slotarrangement 60. The slot arrangement 60 provides means to producerelative rotation for the slip assembly 48, vwhereby the expander sleeveI44 may-be driven into the space between the slips 52 'aessio urgedupwardly to lodge the packet 42 between the head 36 and the pipe 32. Thetubing anchor 22 is lowered into the pipe 32 with the screw 58 riding ina slot 62. The tubing anchor 22 is removed from the pipe 32 by liftingthe anchor means of the wire line 14 with the screw 58 lodged at a point64 or at a point 66 in the slot arrangement 60.

After the tubing anchor is lowered to an appropriate depth within thepipe 32 with the screw 58 at the top of the slot 62, the wire line islifted to send the screw 58 down to the point 64. The wire line 14 isthen slackened and'the screw 58 is permitted to ride up into the slot 63so that the expander sleeve 44 will be driven into the space between theslips '52. The slips will bite tive downward vertical movement of thefingers 46 along the tubing 24.

After the tubing anchor 22 is set in the pipe 32, according to themethod of the invention, wash fluid is circulated down through the pipe32, through the apertures 40 of the circulating head 38, through thetubing 24 and out the lower end of the stinger 26 to erode the material28 out of the fish 30 and to carry it away up the well in the spacebetween the pipe 32 and the well bore 34.

In the operation of the clean-out apparatus shown in Fig. 2 it oftenhappens that material 28 adjacent the internal surface of the fish 30becomes washed out before the material at the center of the fish isloosened. This often causes the material 28 in a solid form to be forceddown to a greater depth into the fish 30. For this reason it isdesirable to move the stinger 26 farther into the fish 30 to place it amost effective distance from the material 28 to continue the washingmethod. It is generally undesirable and too troublesome to move the tubing anchor 2-2 step by step down the unplugged pipe so that the stinger26 will be placed step by step farther into the fish 3% Alternativestinger assemblies are shown in Figs. 3 and 4 which may be employed tosolve this problem.

A stinger assembly 70 is shown in Fig. 3 comprising the tubing 24 with aradially and outwardly extending flange 72 at its lower end. A nozzleassembly 74 is then provided outside of the tubing 24 with a flange 76extending radially inwardly to the external surface of the tubing 24.The flanges 72 and 76 thus cooperate to limit the downward verticalmovement of the nozzle assembly 74. Material 28 pluggingthe fish 30 isalso shown in Fig. 3, the portion of the material adjacent the internalsurface of the fish 34} being washed away. in the operation of thestinger assembly 78 wash fluid is forced down through the tubing 24 andout the lower end of the nozzle assembly 74. Force of the fluid againstthe upper surface of the material 28 prevents the nozzle assembly 74from directly engaging that surface. Material 28 isthus eroded away byflow of the wash fluid through the lower end of the nozzle assembly 24and carried away up the fish 38 between the nozzle assembly 74 and thefish 3d to the top of the fish where it is further carried away up theWell between the well bore 34 and the pipe 32 as indicated by the arrows78 in Fig. 3 and the arrows 8G in Fig. 2.

A similar stinger assembly 82 is shown in Fig. 4 wherein the tubing 24is provided with an inwardly extending flange 84. A nozzle assembly 86,slidable within the tubing 24 is also provided including an outwardlyand radially extending flange 88 to engage the flange 84 and limit thedownward vertical. movement of the nozzle assembly 86. The material 28is shown in the same manner in the fish 30 in Fig. 4 and is eroded awayand carried away in the same manner as described with respect to thestinger assembly70 shown in Fig. 3.

In Fig. 5 an alternative embodiment of the invention is shown. Asillustrated in Figs. 2, 3. and 4, a packer 42 may be fixed to the pipe32 and a nozzle assembly or nozzle forming means 74 or 86 may beprovided, such means being movable with respect to the pipe 32 or thefish 30. In accordance with the invention, novel apparatus is alsoemployed wherein a packer is fixed to a. movable nozzle assembly. Such adevice is shown in Fig. 5 comprising a length of tubing or spout-formingmeans 90 having a circulating head 92 for a top portion and a stinger 94forming its bottom portion. The nozzleforming means 90 is a length oftubing which may be conveniently lowered into the pipe 32 by means ofthe wire line 14. The tubing 90 may be most conveniently lowered intothe well by pumping wash fluid down into the pipe 32, the flow betweenthe tubing 90 and the pipe 32 being restricted by a cylindrical body 96fixed to the tubing. 90 at a point along its length. The body 96 may bemade of a rigid metallic material, or alternatively, of a resilientmaterial. Its function is merely to divert most of the fluid in the pipe32 thru it and preferably to prevent most of the fluid from flowingaround it. After the tubing 90 is lowered into the pipe 32 with thestinger 94 projecting into the fish 30 to clean out the material 28,wash fluid may be circulated down the pipe 32 through apertures 98 inthe head 92 through the tubing 90 and the stinger 94 to erode thematerial 28 out of the fish 30.

It is common to lower tools into pipes such as the pipe 32 on a wireline by two methods. Tools may be lowered into pipe and carried downsimplyby virtue of their own weight or they may be pumped down. In thelatter case, clearance between the tool and the pipe is restricted. If,for example, the tubing anchor 22 is pumped down, means may also beprovided to close the upper end of the tubing 24. However, when washfluid is introduced and forced into the pipe 32 the force on the tubinganchor 22 may be so great that the wire line 14 may be severed and thewhole tubing anchor 22 may fall into the well and cause considerabledamage. In

addition, considerable amount of time, trouble and expense may berequired to recover the tool.

In order to prevent the tubing 90 from being pumped off the wire line14, preferably the body 96 may have the shape as shown as a body 96' inFig. 6. In this embodiment of the invention, the body 96 has an annularshape with a V-shaped cross-section, the vertex of the V being incontact with the internal surface of the pipe 32. Excessive pressureabove the body 96' may thus be relieved by bending movement of the outeredge of the body 96' as indicated by the arrows 99 in Fig. 6. Fluidpumped into the pipe 32 above the body 96' may then be permitted to flownot only through the apertures 98 and the tubing 90 but also between thebody 96 and the pipe 32. Such a device may, of course, be employed withthe tubing anchor 22 as shown in Fig. 2. However, when employed with thetubing 90 as shown in Figs. 5 and 6, the body 96 serves a dual purpose.That is, it provides a seal fixed to the tubing 90 but slidable withrespect to the pipe 32 to permit the tubing 90 to be pumped down thepipe 32 and to restrain flow of fluid between the tubing 90 and the pipe32 when material 28 is being eroded out of the fish 30. However, ifexcessive pressure exists above the body 96', the body also relievesagainst excessive pressure created above it. Thus, it may prevent thetubing 90 from being pumped off the wire'line 14.

A similar safety device is shown in Fig. 7 wherein the tubing 90 isdisposed in a length of pipe 32. The tubing 90 in this case ispreferably provided with a shoulder 102 to support a spring 104 coiledaround the exterior of the tubing 90 at a position just above theshoulder 102.

asssaso apertures 108 conforming to a plurality of apertures 110 in thetubing 90. The body 96' is then fixed to the exterior and at the upperend of the cylinder 106 to perform the same function as illustrated inFig. 6. The body 96 in Fig. may of course be substituted for the body 96as shown in Fig. 7.

The body 96' in Fig. 7 provides the same functions, i.e. to seal thetubing 90 to the pipe 32 and to provide a safety valve for fluid flowbetween the pipe 32 and the body 96'. In addition, should the pressureabove the body 96' become extremely excessive, force on the body 96'will. drive the cylinder 106 down the tubing 90 to compress the spring104. The spring 104 may be compressed to such an extent that theapertures 108 in the cylinder 106 coincide with the apertures 110 in thetubing In this case fluid flow is not only permitted between the body 96and the pipe 32 but also completely through the tubing 90 to its lowerextremity and out the apertures 110 and down the pipe 32 between thetubing 90 and the pipe 32. In this manner a double safety feature isprovided to prevent excessive pressure above the body 96' from severingthe tubing 90 from the wire line 14. As stated previously, the body 96need not necessarily be used with the cylinder 106, the body 96 alsobeing adapted for that use. In this case the only relief given is by themovement of the cylinder 106 to place the apertures 108 over theapertures 110 to provide communication from inside the tubing 90 to thespace outside the tubing 90 between the pipe 32 and the tubing 90 belowthe body 96'.

An alternative embodiment of the invention is shown in Fig. 8 comprisinga circulating head 112 connected from the wire line 14 to a length oftubing 114. A gland 116 is then slidably mounted on the tubing 114 withits downward relative vertical movement limited by a pair of check meansor shear pins 113. The gland 116 is provided with a packing nut 120 toloosen or tighten the packing therein as the case may require. The lowerend of the circulating head 112 is provided with a shoulder 122 to reston the packing nut 120 to prevent the tubing 114 from being lost in thewell in the event that the wire line 14 becomes accidentally severed.The packing nut 120, which is connected to the gland 116, is limited inmovement down the pipe 32 by a shoulder 124 thereon having a seat 126 atthe bottom thereof to engage the lower end of the gland 116. The gland116 may be provided with a resilient O-ring 128 as shown.

It is apparent that the shoulder 124 serves a dual function. It providesmeans to fix the position of gland 116 in pipe 32 and also prevents thegland from falling deep into the well if it should accidentally comeloose from the tubing 114.

The shear pins 118 also serve a dual purpose. In the first place theysimply limit the downward movement of the gland 116 on the tubing 114.In addition, if the gland 116 should happen to become stuck within theshoulder 124, an upwardly directed force may be applied to the wire line14 to pull the tubing 114 through the gland 116 and out of the well. Theinside diameter of the gland 116 is such that a string shot forunscrewing the pipe may be lowered into the fish 30 after the material28 has been cleaned out as shown in Fig. 9. The tubing 114 and the gland116 are shown in Fig. 9 in their operative positions to clean thematerial 28 out of the fish 30. An overshot 200 with slips 201 areprovided at the lower end of pipe 32 to engage fish 30.

As shown in Fig. 9 a packing material 130 is forced into the spacebetween a cylinder 132 forming the gland body and the packing nut 120.If the material 28 should happen to slide down the inside of the fish30, it will be desirable to lower the tubing 114 farther into the fish.For this reason, the tubing 114 is made slidable through the gland 116.In order to overcome excessive friction in the gland 116, however, avalve (not shown) operable to slacking of the wire line 14 may ,beprovided within the circulating head 112 to close the upper end of thetubing 1'14 and thereby permit the tubing 1 14 to be pumped through thegland 116.

It may be desirable to screw into plugged pipe with unplugged pipe.However, in this case it is necessary to provide communication from apoint inside the plugged pipe above the plugging material to a pointoutside the unplugged pipe. For this reason, a sub 134, shown in Fig.10, with apertures 136 may be threaded onto the lower end of theunplugged pipe 32 and into plugged pipe 202, the apertures 136 in thesub 134 providing outlets for wash fluid emanating from the lower end ofthe stinger 138 eroding the material 28 out of the pipe 202. Thematerial is then carried away through the apertures .136 up the wellbore between well'bore 34 and the pipe 32. It will be appreciated thatthe sub 134 should be provided with a seat such as the seat 126 if thetool of Fig. 8 is employed therewith.

It is to be understood that the term nozzle-forming means as referred toherein is not to be limited in definition to means forming afrusto-conical internal surface converging toward an orifice, but thatit means a tube like member to produce a jet of fluid having acrosssectional area substantially smaller than the unplugged pipeinto'which the nozzle-forming means is lowered. In this definition, ajet of fluid is intended to mean that preferably most of the fluidflowing in the pipe also flows inside the nozzle forming means and notaround it between it and the pipe.

It is thus apparent that the method of the invention may be employedwith the use of conventional or novel nozzle-forming means to cleanplugging material from a continuous length of pipe, e.g. see Fig. 10, orfrom a fish disposed in a well bore below pipe such as drill pipe. Themethod requires the use of only a wire line and thus may be performedquickly and inexpensively. The embodiment of the invention shown in Fig.5 also illustrates how simple a form the novel apparatus of theinvention may take. The alternative embodiments illustrated in Figs. 6,7, 8 and 9 also show how a number of novel structures may also beemployed in addition with the clean-out apparatus to prevent suchclean-out apparatus from falling into a well, e.g. by being pumped offof a wire line. The embodiment shown in Figs. 8 and 9, in addition,-isprovided with the shear pins 118 to permit subsequent recoveryoperations even though the gland 116 should become stuck in the pipe 32.The apertures 136 of sub 134 in Fig. 10, of course, need not be machinedtherein, but may be provided by shooting a gun perforator. It is, ofcourse, obvious that many other changes and modifications of theinvention may also be made without departing from the true scope asdefined in the appended claims.

What is claimed is:

1. Hydraulic apparatus for opening a plugged fish to be removed from awell hole comprising a pipe adapted to be extended into said hole, to alocation adjacent the fish to be removed; a fishing tool attached to thelower end of said pipe, said tool including a cylindrical body of thesame diameter as the pipe and a skirt depending from the lower end ofsaid body and formed to an inner and outer diameter greater than theinner and outer diameters, respectively, of the body, said skirt beingadapted to receive the upper end of the fish to be removed; an elongatedtubing extending longitudinally and centrally of said pipe, said tubinghaving its outer surface spaced inwardly a substantial extent from theinner surface of the pipe and body of the fishing tool, said tubingbeing formed open at its lower end for exerting fluid pressuretherethrough against debris accumulating within said fish, the tubingbeing shiftable in the direction of its length within the pipe andfishing tool body and when so shifted extending a distance sufficient tobring the lower end of thetubing to a level lower than the fishreceivingend of the skirt; and means providing a seal interposed between theouter surface of the tubing and the inner surface of said pipe, toprevent a backward flow of flu'idpressure within the pipe exteriorly ofthe tubing, beyond the location of the seal.

2. Hydraulic apparatus for opening a plugged fish to be removed from awell hole comprising a pipe adapted to be extended into said hole, to alocation adjacent the fish to be removed; a fishing tool adapted to beattached to the lower end of said pipe, said tool including acylindrical body of the same diameter as the pipe and a skirt dependingfrom the lower end of said body and formed to an inner and outerdiameter greater than the inner and outer diameters, respectively, ofthe body, said skirt being adapted to receive the upper end of the fishto be removed; an elongated tubing extending longitudinally andcentrally of said pipe, said tubing having its outer surface spacedinwardly a substantial extent from the inner surfacev of the pipe andbody of the fishing tool, said tubing being formed open at its lower endfor exerting fluid pressure therethrough against debris accumulatingwithin said fish, the tubing being shiftable in the a direction of itslength within the pipe and fishing tool body and when so shiftedextending a distance sufficient to bring the lower end of the tubing toa level lower than the fish-receiving end of the skirt; and meansproviding a seal interposed between the outer surface of the tubingaxial bore and engaging said tubing to prevent leakage,

between the tubing and gland.

3. Hydraulic apparatus for opening a plugged fish to be removed from awell hole comprising a pipe adapted to be extended into said hole, to alocation adjacent the fish to be removed; a fishing tool adapted to beattached to the lower end of said pipe, said tool including acylindrical body of the same diameter as the pipe and a skirt dependingfrom the lower end of said body and formed to an inner and outerdiameter greater than the inner and outer diameters, respectively, ofthe body, said skirt being adapted to receive the upper end of the fishto be removed; an elongated tubing extending longitudinally andcentrally of said pipe, said tubing having its outer surface spacedinwardly a substantial extent from the inner surface of the pipe andbody of the fishing tool, said tubing being formed open at its lower endfor exerting fluid pressure therethrough against debris accumulatingwithin said fish, the tubing being shiftable in the direction of itslength within the pipe and fishing tool body and when so shiftedextending a distance suflicient to bring the lower end of the tubing toa level lower than the fishreceiving end of the skirt; and meansproviding a seal interposed between the outer surface of the tubing andthe inner surface of said pipe, to prevent a backward flow of fluidpressure within.the pipe exteriorly of the;tubing, beyond the locationof the seal, said fishing tool including circumferentially spaced slipsafiixed to the inner surface of said skirt inwardly from thefish-receiving end of. the skirt, said slips projecting radially andinwardly of fish and skirt through which fluid forced through the tub-10 ing, and debris forced out of the fish by said fluid, may pass to alocation exteriorly of the drill pipe for flow out of the well hole.

4. Hydraulic apparatus for opening a plugged pipe comprising anunplugged pipe adapted to be extended into a well hole to a locationadjacent the plugged pipe;

means on said unplugged pipe adapted to engage said plugged pipe; anelongated tubing extending longitudinally and centrally of saidunplugged pipe, said tubing having its outer surface spaced inwardly asubstantial extent from the inner surface of the unplugged pipe, saidtubing being formed open at its lower end for exerting fluid pressuretherethrough against debris accumulating within said plugged pipe, thetubing being shiftable in the direction of its length within theunplugged pipe and when so shifted extending a distance suflicient tobring the lower end of the tubing to a level lower than the lower end ofsaid unplugged pipe; and means providing a seal interposed between theouter surface of the tubing and the inner surface of said unpluggedpipe, to prevent a backward flow of fluid pressure within the unpluggedpipe exteriorly of the tubing, beyond the location of the seal, saidmeans comprising an internal, annular shoulder formed upon the innersurface of the unplugged pipe, and a packing gland having an axial borein which said tubing is slidable, said gland being bodily slidable uponthe tube and being proportioned to engage against said shoulder,' thegland having packing means forming a part at least of the wall of saidaxial bore and engaging said tubing to prevent leakage between thetubing and gland.

5. In a well bore having a length of unplugged pipe disposed therein andhaving a length of up-ended debris plugged pipe disposed in the wellbelow the unplugged length of pipe, the method of circulating fluid toerode and carry said debris from said plugged pipe to the surfacethrough a space exterior of said unplugged pipe, said method comprisingthe steps of; providing an opening above the debris to the well bore forexit fluid passage; lowering a length of tubing of smaller externaldiameter than said pipes by means of a wire line into the unplugged pipeand into a position in said pipe so that a portion of said tubingextends from the unplugged pipe into a position in said plugged pipeadjacent the debris; directing a circulating fluid downwardly into saidunplugged pipe and into and through said tubing, increasing the velocityof fluid flow in said tubing by positioning means between said tubingand unplugged pipe for diverting fluid in the unplugged pipe into thesaid tubing; eroding debris out of said plugged pipe by means of theresulting high velocity fluid; circulating said eroded debris and fluidout of said plugged pipe into a space between said plugged pipev andsaid tubing; further circulating said debris and fluid upwardly andthrough the said opening provided for fluid exit passage and to thesurface of the well bore through the annulus space formed by saidunplugged pipe and said well bore; and successively lowering said tubinginto the debris plugged pipe so as to maintain the lower portion thereofadjacent to the upper surface of the remaining debris in the pluggedpipe and thereby eroding and removing remaining debris from the saidplugged pipe.

6. A hydraulic apparatus for opening a debris plugged pipe in a wellbore comprising an unplugged pipe adapted to be extended into a wellbore to a location adjacent to the plugged pipe; a circulating subhaving apertures for fluid passage in the wall thereof connected to saidunplugged pipe, said sub having means adapted to engage said pluggedpipe; an elongated tubing of smaller diameter than said pipes andmovable by means of a wire line in said pipes and extendinglongitudinally within said unplugged pipe; said tubing being shiftablein the direction of its length within the unplugged pipe and when soshifted extending a distance sufiicient to bring the lower end of thesaid tubing to a level lower than the lower end of said unplugged pipeand into successively lower positions in the plugged pipe to erodedebris therefrom; and

means positioned between said unplugged pipe and said tubing fordiverting fluid from within said unplugged pipe under pressure into anupper region of said tubing and out of the lower region thereof atincreased velocity.

7. In a well bore having a plugged pipe disposed therein, hydraulicapparatus for cleaning out material plugging the pipe, the saidapparatus comprising: unplugged pipe means disposed in the well abovesaid plugged pipe; spout-forming means adapted to be raised and loweredon a wire line in said unplugged pipe means so that a portion of saidspout means may be extended from said unplugged pipe means intosuccessive portions of the said plugged pipe; and a fluid-restrictingdevice comprising an annular resilient body having a substantiallyV-shaped cross-section, said body being fixed to said spout-formingmeans 'with the vertex of the V disposed in engagement with the innersurface of said unplugged pipe means adapted to divert circulating fluidfrom the unplugged pipe means into said spout-forming means to causesaid circulating fluid to flow through said spout-forming means atincreased velocity, the upper end of said spout-forming means at alltimes adapted to extend above said restricting device while its lowerend is positioned substantially below the lower end of said unpluggedpipe means and into successively lower portions of the plugged pipe,whereby fluid may be circulated downwardly through said unplugged pipemeans and through said spout-forming means at increased velocity to forma stream that will erode debris out of successively lower portions ofthe plugged pipe and carry said debris to the surface of the well borethrough an annulus between the unplugged pipe and the well bore.

8. In a well bore having a plugged pipe disposed therein, hydraulicapparatus for cleaning out material plugging the pipe, the saidapparatus comprising: unplugged pipe means disposed in the well abovesaid plugged pipe; spoutforming means including a body portion having afirst radial projection on its lower end and another length of tubingextending to the lower end thereof and disposed concentrically with andcontiguous to said body portion, said other length of tubing beingslidable with respect to said body portion and having an opposite andsecond radial projection thereon to engage said first radial portion tolimit the downward movement of said other length of tubing along saidbody portion; said spout-forming means adapted to be raised and loweredon a wire line in said unplugged pipe means so that a portion of saidspout means may be extended from said unplugged pipe means intosuccessive portions of the said plugged pipe; and a fluid-restrictingdevice comprising a tubing anchor adapted to divert circulating fluidfrom the unplugged pipe means into said spout-forming means to causesaid circulating fluid to flow through said spout-forming means atincreased velocity, the upper end of said spout-forming means at alltimes adapted to extend above said restricting device while its lowerend is positioned substantially below the lower end of said unpluggedpipe means and into successively lower portions of the plugged pipe,whereby fluid may be circulated downwardly through said unplugged pipemeans and through said spout-forming means at increased velocity to forma stream that will erode debris out of successively lower portions ofthe plugged pipe and carry said debris to the surface of the well borethrough an annulus between the unplugged pipe and the well bore.

9. In a well bore having a plugged pipe disposed therein, hydraulicapparatus for cleaning out material plugging the pipe, the saidapparatus comprising: unplugged pipe means disposed in the well abovesaid plugged pipe; spoutforming means adapted to be raised and loweredon a wire line in said unplugged pipe means so that a portion of saidspout means may be extended from said unplugged pipe means intosuccessive portions of the said plugged pipe, said spout-forming meansbeing provided with apertures; a fluid-restricting device adapted todivert circulatring fluid from the unplugged pipe means into saidspoutforming means to cause said circulating fluid to flow through saidspout-forming means at increased velocity, the upper end of saidspout-forming means at all times adapted to extend above saidrestricting device while its lower end is positioned substantially belowthe lower end of said unplugged pipe means and into successively lowerportions of the plugged pipe, whereby fluid may be circulated downwardlythrough said unplugged pipe means and through said spout-forming meansat increased velocity to form a stream that will erode debris out ofsuccessively lower portions of the plugged pipe and carry said debris tothe surface of the well bore through an annulus between the unpluggedpipe and the well bore; collar means slidable on said spout-formingmeans; and resilient means to urge said collar means upwardly along saidspout-forming means to cover said apertures, said fluid restrictingdevice being fixed to said collar means, whereby said collar means maybe forced downwardly against said resilient means to open said aperturesto relieve stress on said lowering means when the fluid pressure onsaid'fluid-restricting device becomes excessive.

10. An apparatus for eroding and removing debris from a length of anup-ended debris plugged first pipe in a well bore by means of acirculating fluid which erodes and carries the said debris from the saidfirst pipe to the surface through a space exterior of the saidapparatus, comprising: a second pipe of smaller diameter than the wellbore and extending downwardly from an upper portion of the well boreadjacent to the upper end of said first pipe, a circulating sub attachedto said second pipe and forming a fluid opening between said first andsecond pipes, a length of third pipe attached to a wire line extendingfrom above the well bore and being movable by means of said line, saidthird pipe being of smaller diameter than said first and second pipesand positioned in said second pipe for longitudinal movement therein, sothat a substantial portion of the length of said third pipe may beextended from the second pipe into successively lower positions in saidfirst pipe, and means for diverting circulating fluid from said secondpipe under pressure into an upper region of said third pipe and out of alower region thereof at increased velocity into said first pipe, wherebyfluid may be circulated downward through said second pipe and throughsaid third pipe at increased velocity into successively lower positionsin said first pipe to erode debris therefrom and carry said debris fromsaid first pipe up to the surface through a passage formed between saidsmall diameter third pipe and said first pipe and then through anopening between said first and second pipes and thence to the surface ofthe bore hole through an annulus between the second pipe and the wellbore.

11. Hydraulic apparatus for opening a debris plugged pipe comprising anunplugged pipe adapted tobe extended into a well hole, to a locationadjacent to the plugged pipe; means on said unplugged pipe adapted toengage said plugged pipe; an elongated tubing extending longitudinallyand centrally of said unplugged pipe, said tubing having its outersurface spaced inwardly a substantial extent from the inner surface ofthe unplugged pipe, said tubing being formed open at its lower end forexerting fluid flow therethrough against debris accumulating within saidplugged pipe, the tubing being shiftable in the direction of its lengthwithin the unplugged pipe by means of a wire line and when so shiftedextending a distance suflicient to bring the lower end of the tubing toa level lower than the lower end; of said unplugged pipe and intosuccessive lower positions in said plugged pipe; and means providing aseal interposed between the outer surface of the tubing and the innersurface of said unplugged pipe, to divert circulating fluid flowingdownwardly in said unplugged pipe into said tubing and therebyincreasing the velocity of flow of said circulating fluid to' provide ahigh velocity stream of said fluid suitable for eroding debris out of alength of the plugged pipe and carrying said debris to the surface ofthe References Cited in the file ofthis patent UNITED STATES j PATENTSScheurer Dec. 20, 1921 Ligon Ian. 12, 1926 14 Otis July 20, .1937 PieperNov. 7, 1939 Burt Apr. 9, 1940 Mallory Oct. 15, 1940 Osborn Feb. 24,1942 Stewart et al.- July 29, 1953 Huber June 12, 1956 House et a1. Apr.8, 1958

